Read a Google Sheet range

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover readOnly/idempotent/openWorld, but the description goes further by disclosing the authorization model (file-picker hand-off required for pre-existing spreadsheets) and a concrete error-recovery path for the not-found case, plus the return shape (2-D array of values).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core action and scoping rule, then the parameter alternatives, then error handling. Dense with em-dashes and parentheticals, which makes it slightly harder to scan, but every sentence carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Return format is stated and the access model is thorough. The one gap is tab selection: for a multi-tab spreadsheet it never says which tab is read or that the agent may need list_sheet_tabs first.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% so the baseline is 3, but the description adds meaning the schema does not: spreadsheetId and sheetUrl are alternatives ('OR'), and it states where each value originates (create_sheet for the id, a pasted URL for sheetUrl).

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Read cells from a Google Sheet') and scopes it to reachable files. An agent can distinguish this from update_sheet, append_to_sheet, and list_drive_files without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly covers when the tool works: sheets Hermoso created or ones the user handed over via the file picker, and directs the agent to list_drive_files to obtain the id. It also names the failure condition ('file not found' means the user hasn't picked it) and prescribes the correct next action instead of retrying.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.